That's awesome, thank you!
You can go ahead an try to fix one of our issues. We have introduced a tag 'Newcomer Friendly' for issues we believe are suitable to get started with Shoes contributing. These issues either are relatively easy to accomplish or don't depend on a lot of other shoes code (e.g. completely new features) so that it's easier to get started. Please feel free to tackle any issue - we will help you if needed. The tag is just a suggestion! =)
Also there is a list of samples that already work at samples/README, along with all the other samples. You can try to get a new sample to run. In order to do so you can run rake non_samples to run a random sample we think does not work. If you just want to list the non working samples you can also run rake list_non_samples.
With all you do, please make sure to write specs as Shoes 4 is developed TDD-style (see the Running Specs section below). So make sure that you don't break any tests :-)
If you feel unsure about testing or your implementation just open an issue or a pull request. Pull requests don't need to be done - they are great discussion starters! We're happy to help you get your contribution ready to be merged in order to help build Shoes 4!
In fact we greatly appreciate early pull requests to review code and help you find your way around Shoes 4! =)
If you have questions, also feel free to drop by on the #shoes channel on FreeNode irc. People might not respond instantly, but after some time someone will respond :-)
It sometimes is also a good way to refactor some code or write some specs in order to get familiar with a project. If you want to try this approach you can have a look at our Code Climate to find candidates for refactoring or after running the specs locally take a peak into the coverage directory and open index.html - it shows you our current coverage data. See something that isn't covered and maybe you can write a spec for it?
Refer to the README for information on how to run the specs, that were mentioned before :-)